Honestly, most of these cards are pretty nice. Hats is very situational and sometimes downright unusable, that is why there is no way I'd ever play that thing.
Mefist was talked about enough, good card that was not well known enough.
Marauding Captain could be awesome, but again, it can always happen that you don't have a tuner ready to Synchro and the XYZ-ing is done better by Tour Guide, so Captain is somewhat useless.
Faust Bargain can be a pain in the ass, Just yesterday my Worm King fell victim to it and left me wide open for direct attacks. It pops an opponent's monster, special summons an own AND you can then normal summon yet another one to either go for massive attack damage, or XYZ into something huge.
Reptar, could you please let the adults discuss and go behave like a kid somewhere else? Thanks.